Last August, when I was at the Sci Foo camp, Paul Sereno brought along the skull of one of his latest discoveries…and whoa, is it ever a weird one. This is Nigersaurus taqueti, an herbivorous dinosaur with specializations for ground-level grazing. Look at this picture; in reality, it’s even more striking.

Those jaws and teeth—they are so neatly squared off and flat-edged. In addition, the skull itself on the spinal column is turned habitually downward. This is a creature that kept its face pressed to the ground as it nibbled its way across the landscape.

Another feature that was apparent is that the skull is awesomely light — it’s mostly empty spaces with a delicate webwork of bony struts holding it together. It’s so specialized it’s almost comical, and you can imagine something like this appearing on the Flintstones as a lawn mower or hedge trimmer.

Comments

This is what was predicted for a low, or ground grazer to look like by many people.

It’s way, way beyond all descriptions. The lower temporal fenestra is in front of the eye. The upper temporal fenestra is gone. All teeth, without one exception, are part of the precisely straight toothrows that are broader than the rest of the skull. The snout points almost vertically downward. The vertebrae are hollow — not foamy, but hollow. It boggles the mind!

Evidence of massive callouses on the feet of prehistoric men from their use as car brakes?

Not going to fossilize, but we can expect specializations in the ankles and knees, at least…

Wow, that is strange. Is there anything alive today with a jaw like it?

Nope — neither alive nor dead.

I hope to hear more about how this thing likely fit in.

Fig. 4 of the paper is a tree.

They think it ate mosses and ferns.

The paper says ferns and horsetails and doesn’t mention mosses… that said, horsetails are actually ferns…

Is this common in biology?

No.

Is it a requirement of the journal?

Yes, and it’s a good idea.

may I ask why the reference cited dismisses the possible use of gastroliths in sauropods?

People used to assume that all rounded pebbles found near a sauropod were gastroliths. That isn’t the case. Even when found inside a skeleton, they are often far too soft for such use, the number and position is never right, and so on. It just doesn’t fit together. Incidentally, crocodiles have gastroliths but don’t use them for chewing; I saw an X-ray movie about this at a congress in May.

This is what was predicted for a low, or ground grazer to look like by many people.

It’s way, way beyond all descriptions. The lower temporal fenestra is in front of the eye. The upper temporal fenestra is gone. All teeth, without one exception, are part of the precisely straight toothrows that are broader than the rest of the skull. The snout points almost vertically downward. The vertebrae are hollow — not foamy, but hollow. It boggles the mind!

Evidence of massive callouses on the feet of prehistoric men from their use as car brakes?

Not going to fossilize, but we can expect specializations in the ankles and knees, at least…

Wow, that is strange. Is there anything alive today with a jaw like it?

Nope — neither alive nor dead.

I hope to hear more about how this thing likely fit in.

Fig. 4 of the paper is a tree.

They think it ate mosses and ferns.

The paper says ferns and horsetails and doesn’t mention mosses… that said, horsetails are actually ferns…

Is this common in biology?

No.

Is it a requirement of the journal?

Yes, and it’s a good idea.

may I ask why the reference cited dismisses the possible use of gastroliths in sauropods?

People used to assume that all rounded pebbles found near a sauropod were gastroliths. That isn’t the case. Even when found inside a skeleton, they are often far too soft for such use, the number and position is never right, and so on. It just doesn’t fit together. Incidentally, crocodiles have gastroliths but don’t use them for chewing; I saw an X-ray movie about this at a congress in May.

Canadians also may pronounce herb as ‘erb and herbivore as ‘erbivore, but like so much of Canadian English, the phoneme is in free variation between the US and UK pronunciations.

But, back to grasses if I may. If this critter was grazing early grasses, they were likely not as siliceous as later grasses were. Then again, would a dino like this be worried about tooth wear or would it just keep replacing teeth as they wore out? Permanent teeth are a mammilian adaptation, aren’t they?

Yep. That’s the non-misused version. Aspiration of [p] produces an English p (as opposed to a French one). Aspiration of nothing produces [h]. The English p contains a [h] sound, sort of. And that’s my point.

why the depictions of nigersaurus in the flesh show them having spiky things down their toplines?

Because they were found in a particularly well-preserved fragment of a relative of Diplodocus. Nigersaurus is fairly closely related, so there’s a reasonable chance it had those spikes, too. (They don’t contain bones.)

If this critter was grazing early grasses

Highly unlikely, because it’s much older.

Permanent teeth are a mammilian adaptation, aren’t they?

Yep, and as the paper says, Nigersaurus had sped up the rate of tooth replacement to once per month.

Yep. That’s the non-misused version. Aspiration of [p] produces an English p (as opposed to a French one). Aspiration of nothing produces [h]. The English p contains a [h] sound, sort of. And that’s my point.

why the depictions of nigersaurus in the flesh show them having spiky things down their toplines?

Because they were found in a particularly well-preserved fragment of a relative of Diplodocus. Nigersaurus is fairly closely related, so there’s a reasonable chance it had those spikes, too. (They don’t contain bones.)

If this critter was grazing early grasses

Highly unlikely, because it’s much older.

Permanent teeth are a mammilian adaptation, aren’t they?

Yep, and as the paper says, Nigersaurus had sped up the rate of tooth replacement to once per month.

Thanks Sven. As soon as I hit ‘Post’ it occurred to me that they would of course replace their dentition (as most if not all reptiles do.)

I didn’t know that horsetails were silaceous though. I just know next Sunday there’ll be a new Simpsons episode with Lenny saying “Ow! My eye! I’m not supposed to get silaceous horsetails in it!” and then I’ll feel really stupid.

As for Randi’s comment: I’m still pissed at the way Indo-European bastardised Nostratic.

By the way Randi, in proper English, ‘bastardise’ is spelled with an ‘S’, not a ‘Z’.

I call your attention to the words “accompanies or comprises” in the definition you and I have both cited. The word “accompanies” covers the aspiration of some (not all) English “p”s, or the classical pronunciation of Greek phi. But what of an “audible breath that comprises a speech sound”? I submit this is, in fact, an [h].

Brownian,

If “bastardise” is the proper English spelling, why does the Oxford English Dictionary insist on spelling it “bastardize”?

Modern mammals that browse or graze, and that must sort through or move inedible debris (horses and giraffes, for example), have very mobile and sensitive upper lips. From the reconstruction, it doesn’t look as if this is the case for Nigersaurus; what’s the current thinking (if any) on facial muscle structure and function in sauropods?

Don’t take the ruminants too seriously. They lack upper incisors; they gather plants with their lips and then rip them off with their lower incisors and a horny ridge in the place where the upper incisors would be. Not so in Nigersaurus, which seems to have done the gathering and the cutting at once, as usual. Like a lawnmower.

In the UK and elsewhere, the rule is a bit complicated to spell out. It’s “a” before a single-syllable word with a sounded “h” or a word of more than one syllable with a sounded “h” and a stress on the first syllable.

But in “hippopotamus” the stress is on the third syllable…

IMHO the use of “an” in front of pronounced h is just a failed effort to make English look even more like French than it already is. Or does anyone natively speak according to this rule?

Modern mammals that browse or graze, and that must sort through or move inedible debris (horses and giraffes, for example), have very mobile and sensitive upper lips. From the reconstruction, it doesn’t look as if this is the case for Nigersaurus; what’s the current thinking (if any) on facial muscle structure and function in sauropods?

Don’t take the ruminants too seriously. They lack upper incisors; they gather plants with their lips and then rip them off with their lower incisors and a horny ridge in the place where the upper incisors would be. Not so in Nigersaurus, which seems to have done the gathering and the cutting at once, as usual. Like a lawnmower.

In the UK and elsewhere, the rule is a bit complicated to spell out. It’s “a” before a single-syllable word with a sounded “h” or a word of more than one syllable with a sounded “h” and a stress on the first syllable.

But in “hippopotamus” the stress is on the third syllable…

IMHO the use of “an” in front of pronounced h is just a failed effort to make English look even more like French than it already is. Or does anyone natively speak according to this rule?

Also, I’d guess that the lack of facial muscles to move the upper lip would limit the flehmen response, observed in many mammals, which is used to facilitate transfer of pheromones to the vomeronasal organ.

Sure. But then, birds lack the vomeronasal organ… I’m not sure if it leaves traces on the skull bones…

Watch a horse graze some time…it pushes leaves, sticks, and other debris away with the upper lip, and shears off grass blades between upper and lower incisors.

Dinosaurs generally seem to have done without that. (Especially the beaked ones, of course.)

Also, I’d guess that the lack of facial muscles to move the upper lip would limit the flehmen response, observed in many mammals, which is used to facilitate transfer of pheromones to the vomeronasal organ.

Sure. But then, birds lack the vomeronasal organ… I’m not sure if it leaves traces on the skull bones…

Watch a horse graze some time…it pushes leaves, sticks, and other debris away with the upper lip, and shears off grass blades between upper and lower incisors.

Dinosaurs generally seem to have done without that. (Especially the beaked ones, of course.)